Traditionally, there are certain requirements for establishing a roaming relationship between two wireless communication network operators. These requirements include, network connectivity (for example, SS7 and/or Internet Protocol (IP)), a procedure for exchanging billing information, and a commercial roaming agreement (such as AA12-14 or AA31). These requirements must be met before International Roaming Expert Group (IREG) and Transferred Account Data Interchange Group (“TADIG”) tests can be applied. With reference to FIG. 1, a traditional roaming scenario 100 is illustrated. An operator A 102 has an International Roaming Agreement 104 with an operator B 103. The operator A 102 has a fixed network 106A, a GSM system 108A, including a Visited Location Register (VLR) and a Home Location Register (HLR), an EDP center 110A, a billing system 112A, and finance software and hardware 114A. The operator B 103 has a fixed network 106B, a GSM system 108B, including a Visited Location Register (VLR) and a Home Location Register (HLR), an EDP center 10B, a billing system 112B, and finance software and hardware 114B. A subscriber 118 is a subscriber of operator B, but is roaming on the network of operator A. A subscriber 116 is a subscriber of operator A, but is roaming on the network of operator B.
As shown, the operators A and B communicate according to IREG and TADIG tests.
In voice roaming, network connectivity is established by International Switch Center (ISC) carriers or by direct connection. However, connectivity is generally the easiest part of establishing roaming. The more time time-consuming and/or difficult part is establishing a commercial agreement between the two operators before IREG and TADIG testing can proceed. Often, it is not a high priority for network operators to deal with smaller operators to set up roaming relationships. In addition, often it is not a high priority for network operators to set up roaming relationships with other operators in countries where the network operator already has at least one existing roaming relationship.
One approach to facilitating roaming is to piggyback on previously established roaming relationships, or partnerships. The partner operator is often called the sponsoring operator, and the piggybacking operator is often called the sponsored operator.
All current solutions that allow a sponsored operator to piggyback on the roaming relationships of a sponsoring operator only work for voice and Short Message Service (SMS) roaming. In these solutions, Message Application Part (MAP) signaling between the sponsored operator and the targeting roaming partner are relayed through a signal gateway that “fools” the targeting roaming partner into think it is dealing with the sponsoring network. For outbound roamers of the sponsored operator, a sponsoring operator IMSI is used in a dual IMSI SIM when roaming so the IMSI-Sponsoring is being replaced by the corresponding IMSI-Sponsored when the MAP signal is relayed through the signal gateway. The MAP signaling relay can also control MT-calls to inbound roamers from a target roaming partner to be routed through the sponsoring operator if desired.
While these prior solutions can be extended to deal with CAMEL and GPRS MAP signaling, no existing solutions allow a sponsored operator to piggyback on a sponsoring operator's GPRS roaming relationships. GPRS roaming involves both signaling and data sessions.